I’ve recently finished it, and I recommend it to everyone. What follows is a summary plus a few thoughts of my own. It’s a long summary, but the book deserves it.

The theme of Enlightenment Now is contained in its subtitle: it is that reason, science and humanism lead to progress. The corollary is: keep it up!

To elaborate, the message of the book is that reason, science and humanism—which Pinker identifies as the key themes of the Enlightenment—have, historically, led to massive progress in almost every area of life, and that they are our best means of continuing this progress into the future. But these ideals are not consistently upheld, and are often under attack. Therefore, we need to fortify and defend them.

Against what exactly? In the opening chapters, Pinker calls out a number of counter-Enlightenment ideas:

Religious faith

The idea that people are “the expendable cells of a superorganism” (which I would call “collectivism”, although Pinker doesn’t use that term)

What he calls the “romantic Green movement”, which “subordinates human interests to a transcendent entity, the ecosystem” (in contrast to “Enlightenment environmentalism” or “humanistic environmentalism”)

“Declinism”, the idea that civilization “is in steady decline and on the verge of collapse”

An anti-science movement that denounces science for encroaching on the domain of religion or values, or blames it for social ills from racism to war

Progress is central to Pinker’s argument: it is the proof that the Enlightenment is working. The belief that the world is corrupt and in decline motivates a desire for violent revolution and upheaval: smash the system, burn it all down, because nothing could be worse than what we have. What we need is not to destroy the institutions of modernity that have brought us out of the caves to where we are today, but to keep making incremental progress within their framework.

Unfortunately, declinism is all too seductive a view, owing in part to negativity bias, especially in the news (“if it bleeds, it leads”), and availability bias, which causes us to think that bad things are more common just because we hear about them all the time. We need to counter this with careful analysis of the data.

Thus, the bulk of the book is devoted to an empirical analysis of human progress along several dimensions—practical, intellectual and moral—including:

Life: Life expectancy is up, from a world average of less than 30 years in the mid-18th century to over 70 years today; and the increases are seen by all age groups and all continents. Child mortality and maternal mortality in particular have been drastically reduced: “for an American woman, being pregnant a century ago was almost as dangerous as having breast cancer today.”

Health: The threat of infectious disease has been greatly reduced via sanitization, sterilization, vaccination, antibiotics, and other scientific and medical advances, which together have saved billions of lives.

Sustenance: Hunger and famine were a normal part of life throughout most of history. Today, people have access to, on average, over 2,500 calories per day (including an average of 2,400 in India, 2,600 in Africa, and 3,100 in China). And the extra food isn’t all going to the wealthy; measures of stunted growth and undernourishment are declining in some of the world’s poorest regions, and worldwide deaths from famine are also down. Technology was critical in this achievement: mechanization of farming, synthetic fertilizer (thanks especially to the Haber-Bosch process), better crop varieties (thanks to Norman Borlaug and his Green Revolution), and now genetic engineering. The fall of Communism was also significant, since “of the seventy million people who died in major 20th-century famines, 80 percent were victims of Communist regimes’ forced collectivization, punitive confiscation, and totalitarian central planning.”

Wealth: Gross World Product was stagnant or slowly growing for most of human history, but it has grown “almost two hundredfold from the start of the Enlightenment in the 18th century.” And again, the increases are not only seen in a minority of the world. Western countries pulled away from the rest first, starting in the 18th century, in what is known as the Great Escape (from the Malthusian trap). Pinker attributes this achievement to science; institutions that create open economies by protecting rule of law, property rights, and enforceable contracts; and a change in values that conferred “dignity and prestige upon merchants and inventors rather than just on soldiers, priests, and courtiers.” But the Great Escape was followed in the 20th century by the Great Convergence, as poor countries around the world catch up in economic progress and close the gap. In all, the portion of the world living in “extreme poverty” (using the definition of $1.90/day in 2011 international dollars) has fallen from almost 90% in 1820 to 10% today.

Safety: Deaths from virtually all kinds of accidents have drastically fallen. Deaths from motor vehicle accidents alone are down 24 times since 1921; pedestrian deaths and plane crashes are also down. Workplaces are safer. Deaths have decreased from falls, fire, drowning, you name it. Even natural disasters kill fewer people than they used to, as better technology and practices make us safer from everything from earthquakes to lightning strikes.

Quality of life: Work hours have decreased from over 60 hours per week in both the US and Western Europe in 1870, to around 40 hours today. Housework has decreased from 58 hours per week in 1900 to 15.5 hours in 2011, liberating everyone from drudge work, although owing to who historically has performed housework, this is in practice a great liberation of women. As a result, people report more hours of leisure, and more are retiring in old age. Not only our time but our money has been liberated: spending on necessities in the US is down from over 60% of disposable income in 1929 to about a third in 2016. And as a result of economic progress and better technology, people are doing more travel (including international travel), eating more varied and interesting diets, and have much greater access to the knowledge of the world.

Peace: In Pinker’s previous book, The Better Angels of our Nature, he chronicled the decline of violence and its causes. War between great powers has not occurred since World War 2, and the wars that rage today cover less of the world than in the past. Deaths are down from both battles and genocide. And violent crime has been reduced as well. He credits these declines to causes including the advancement of reason and education, the spread of global commerce, and international forums such as the UN.

Democracy: Democracy is taking over the world (that is, democratic republics, as opposed to authoritarian regimes). After suffering setbacks from socialist regimes in the mid-20th century, it is rebounding, with the defeat of Nazism followed by the fall of Communism. Two-thirds of the world’s population now lives in “free or relatively free societies”, vs. one percent in 1816 (according to projects that track this sort of thing, such as the Polity Project).

Knowledge: Around the world, children are going to school longer, and literacy is on the rise. Women are closing the education gap with men, as more cultures decide to educate their girls. Even IQ scores are increasing (a phenomenon known as the Flynn Effect), likely as a result of the spread of education.

He makes this case with dozens of charts and far more data and analysis than a summary can do justice to, much of it sourced from Max Roser’s Our World in Data and similar projects.

Along the way, Pinker provides rebuttals for a number of counterarguments to this story of progress:

Isn’t all this progress just accruing to the rich and increasing inequality? First, Pinker points out, inequality is “not a fundamental component of well-being”, like health, prosperity, knowledge and peace. What matters more is wealth and fairness, and these things are not incompatible with some inequality. Moreover, some inequality is a natural consequence of economic progress, and indeed decreases in inequality often come from economic and humanitarian disasters: “mass-mobilization warfare, transformative revolution, state collapse, and lethal pandemics.” Finally, he notes that global inequality is actually falling (thanks to the Great Convergence), and welfare spending in all developed countries is steadily rising.

Isn’t all this progress just leading to “mindless consumerism” and shallow, empty lives? No, Pinker argues, people are devoting their disposable time, money and energy to meaningful values, such as connecting with loved ones, seeing the world, increasing their knowledge, and creative self-expression.

But what about the Easterlin paradox? This is the claim that, although richer people within a country are happier than poor people, richer countries are not happier than poor ones, and countries don’t get happier over time as they get richer. This has been attributed to the “hedonic treadmill”, in which we reset our expectations at each new level of achievement, thus never getting happier even as our lives get objectively better; and to social-comparison theories of happiness, in which our happiness is based on comparing our situation to others’. However, the Easterlin paradox was proposed in 1973. With more data since then and better analysis, we can see that it doesn’t hold up, indicating that happiness is more closely tied to objective well-being than we might have feared.

Aren’t people lonelier and more disconnected in our digital age? Isn’t there a crisis of escalating anxiety, depression and suicide? No. Pinker looks at the data and concludes that many of these problems are decreasing, with others relatively steady; none are increasing significantly, certainly not to indicate a crisis of the modern age.

But aren’t we destroying the environment? Pinker’s response here is insightful and nuanced. First, he distinguishes between the “quasi-religious ideology” of “greenism”, and a view which may be called “ecomodernism”, “ecopragmatism”, “Enlightenment environmentalism”, or “humanistic environmentalism”. Greenism sees humans as a scourge upon the pristine Earth, pits itself against science and technology, and calls for degrowth and deindustrialization. Ecomodernism focuses on the benefits that technology provides for humanity, and seeks to use technology itself to reduce environmental harm, while recognizing that some level of pollution is necessary and acceptable. While he doesn’t say it explicitly, my interpretation of the difference is that ecomodernism seeks to preserve the environment for the purpose of human flourishing (consistent with the Enlightenment humanism that Pinker keeps returning to), whereas greenism seeks to preserve untouched nature as an end in itself, above and apart from humans.

He goes on to point out that the greenist movement has a history of failed predictions of catastrophe, such as the “population bomb” Paul Ehrlich warned of in the 1960s that was supposed to lead to mass famine by the 1980s, or the related fears that the world was running out of natural resources. And he notes that many measures of environmental harm are on the decline, including pollution, deforestation, and oil spills. However, he believes that some environmental threats are real and serious, in particular global warming. He advocates, not scaling back the world’s energy use (which would threaten many of the measures of progress discussed above), but technology: shifting to nuclear power, deploying carbon capture techniques, and possibly a limited amount of direct climate engineering.

What about terrorism? Pinker sees terrorism as a real threat, but a minor one, claiming many fewer lives than battles or even accidents. He looks at data to show that it is not increasing, and cites studies saying that it is generally not successful: terrorists rarely achieve their strategic goals in the long run. He concludes that it is a problem, but not a catastrophe or a threat to civilization.

What about existential threats from modern or future technology? For instance, the threat of an AI superintelligence or a civilization-ending bio- or cyber-terrorist attack? With the caveat that we cannot prophesy the future, Pinker concludes that there are real threats, but that they are overhyped; some damage is possible, but the threat of extinction is very small. The biggest threat to humanity, he says, is nuclear war (for which he recommends continuing the trend of disarmament, and the other trends that have made war in general less common). He doesn’t recommend ignoring AI safety or counter-bioterrorist programs, but he says there is a real danger of overhyping threats: it can cause misallocations of limited resources, and it can lead to despair from the public who conclude that the world is likely to end literally within their lifetimes.

Having thus made the case for progress, Pinker returns to the ideas that provided its foundation, which he identifies as key themes of the Enlightenment, and calls for these ideas to be strengthened and defended against counter-Enlightenment movements in the culture.

Reason, he points out, is fundamental, and anyone who opposes it is, by definition, unreasonable. Some argue that the existence of cognitive biases, such as those popularized by Daniel Kahneman’s Thinking Fast and Slow, prove that humans are irrational (“predictably irrational”, even). But these biases don’t prevent us from being rational, they’re simply an obstacle to good thinking that we can overcome—using reason. Another obstacle to a rational society is that many people drop reason when it comes to political issues, professing beliefs not as an honest assessment of truth but as an act of allegiance or loyalty to an ideology or tribe. Overall he calls for better education and training on critical reasoning and cognitive debiasing, a more empirical approach to prediction, and the depoliticization of issues as much as possible.

Science, he says, is the proudest accomplishment of our species. Science is distinguished from reason in general by two ideals: that the world is intelligible, and that observation and evidence are the basis of understanding it (the latter is my formulation, he says “we must allow the world to tell us whether our ideas about it are correct”). He defends science against claims that it is to blame for problems such as racism or eugenics. And he calls for science and the humanities to be more integrated, to the benefit of both, rather than seeing themselves as being at odds or in competition.

Humanism, finally, is “the goal of maximizing human flourishing—life, health, happiness, freedom, knowledge, love, richness of experience.” It is a non-religious basis for ethics. It is neither utilitarian (although he admits it has that flavor) nor deontological. It is the standard of value for the entire book, and it is a standard, he says, that people of different races, religions and nationalities can agree on. It clashes, however, with two alternatives. One is theistic morality, which Pinker argues against on the grounds that God does not exist, and that even if he did, he would not be a better source of morality than reason. He argues further against the “faitheists” who don’t believe in God but want to accomodate religion as a source of morality or because of a supposed psychological need for mystical belief. The second enemy of humanism is what he calls “romantic heroism”, which is “the ideology behind resurgent authoritarianism, nationalism, populism, reactionary thinking, even fascism” and which he attributes in large part to Nietzsche. This is the ideology he sees behind the rise of Trump.

Going back to the data, he concludes that long-term trends are working against both theism and authoritarian populism. But a clear and consistent theme of the book is that all of this progress, all these positive trends, are not automatic and must not be taken for granted. His message is not “don’t worry everybody, sit back and relax,” but rather: “let’s do more of what’s working (and not start going in reverse).” To do that, we need to not only keep researching, inventing and building. We also need to rededicate ourselves to reason, science and humanism.

In my opinion, Enlightenment Now is just what the world needs right now. It is a defense of the ideas and values that have created the modern world, and a defense of that world itself. I don’t agree with every word of it, but I agree with its theme and essence.

The weakest aspect of the book, to me, is its morality. “Humanism” is a great start, because it sets the right standard: human life and everything that helps people thrive and prosper. But Pinker largely ignores issues of individualism vs. collectivism, and egoism vs. altruism, that I see as core to the ideological struggles of the modern world.

And closely related, Pinker falls short of painting a truly inspiring, motivating picture, a heroic ideal to strive for. He himself indicates this in the final pages of the book, when he writes: “The case for Enlightenment Now is not just a matter of debunking fallacies or disseminating data. It may be cast as a stirring narrative, and I hope that people with more artistic flair and rhetorical power than I can tell it better and spread it farther.” I hope they do, as well.

But overall, this is a great book, full of profound truths, meticulously researched, lucidly argued, and entertainingly written. Everyone who cares about the big issues of human life, society, politics and culture should read it.